1. Field of the Invention
The present invention relates to microwave ovens and, more particularly, to a microwave oven provided with a tray holding unit which stably holds a cooking tray and a tray guide of the microwave oven so as to prevent the cooking tray and the tray guide from moving from their original positions regardless of vibration and impact applied to the microwave oven, during for example, where the microwave oven is carried by a moving vehicle.
2. Description of the Related Art
A microwave oven is an electrically operated oven which heats and/or cooks food contained in its cooking cavity using high-frequency electromagnetic waves generated by the oscillation of a magnetron installed in a machine room. That is, during an operation of the microwave oven, the magnetron inside the machine room of the microwave oven radiates the high-frequency electromagnetic waves, so-called “microwaves,” through the cooking cavity. The microwaves thus penetrate food so as to repeatedly change the molecular arrangement of moisture laden in the food. That is, the molecules of the moisture are vibrated to generate a frictional heat within the food to cook the food.
Microwave ovens are typically designed to be operated by AC power and used in a kitchen having an AC power supply. However, in recent years, a microwave oven operated by DC power has been proposed and used in both indoors (at home or restaurants) and outdoors (in a vehicle or boats).
FIG. 1 shows the construction of a conventional microwave oven. The conventional microwave oven comprises a cabinet 1 which forms the outer appearance of the microwave oven and a cooking cavity 2 which is defined inside the cabinet 1 with an opening at front and used for cooking food therein. A machine room 3 is defined inside the cabinet 1 at a position under the cooking cavity 2, and receives a variety of devices used for generating microwaves, which are transmitted into the cooking cavity 2 to heat and cook the food inside the cooking cavity 2.
A cooking tray 4 is set on a bottom of the cooking cavity 2 and seats food thereon. A tray guide 5, with a plurality of rollers 6, is set between the cooking tray 4 and the bottom of the cooking cavity 2 to rotatably support the cooking tray 4 on the bottom of the cooking cavity 2.
Seated in the machine room 3 are a magnetron 7 which generates microwaves and a drive motor 9 which rotates the cooking tray 4 set in the cooking cavity 2. The microwave oven also has a wave guide 8 which guides the microwaves from the magnetron 7 into the cooking cavity 2.
In an operation of the microwave oven, microwaves generated from the magnetron 7 are transmitted into the cooking cavity 2 through the wave guide 8, while the cooking tray 4 loaded with food thereon is rotated by the drive motor 9. In such a case, the cooking tray 4 is slowly rotated at a low speed under the guide of the tray guide 5, and the food is heated and cooked by the microwaves.
In such a conventional microwave oven, the tray guide 5 having the rollers 6 is simply laid on the bottom of the cooking cavity 2, and so it is undesirably movable in horizontal and vertical directions. In addition, the cooking tray 4, coupled to a rotating shaft of the drive motor 9, is laid on the rollers 6 of the tray guide. Thus, the cooking tray 4 is also undesirably movable in horizontal and vertical directions. Therefore, the cooking tray 4 and the tray guide 5 may be forcefully moved from their original positions to be damaged or broken while being transported by, for example, a moving vehicle. In addition, when the cooking tray 4 and the tray guide 5 are moved in horizontal and vertical directions due to the moving vehicle (i.e., a mobile home), they also generate frictional noises, upsetting those around the microwave oven.